溶液中巯基苯并噻唑、咪唑和恶唑反应性的理论研究  

Theory study on chemical reactivity of 2-mercaptobenzothiazole,2-mercaptobenzoxazole and 2-mercaptobenzimidazole in solution

作　　者：刘广义[1] 詹金华[1] 钟宏[1] 夏柳荫[1] 王帅[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《中国有色金属学报》2010年第11期2248-2253,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家高技术研究发展计划资助项目(2007AA06Z122);国家重大基础研究发展计划资助项目(2007CB613602);国家自然科学基金资助项目(50604016);全国优秀博士学位论文作者专项资金资助项目(2007B52);教育部"新世纪优秀人才支持计划"资助项目(NCET-08-0568);国家"十一五"支撑计划资助项目(2007BAB22B01)

摘　　要：在B3LYP/6-31+G(d,p)水平,对2-巯基苯并噻唑(MBT)、2-巯基苯并恶唑(MBO)和2-巯基苯并咪唑(MBI)的真空结构进行优化,然后采用积分连续介质模型(IEF-PCM)进一步优化它们及其相应离子在水溶液(介电常数为78.39)中的结构;通过反应中心原子电荷以及前线分子轨道能量和组成分析O、N、S杂原子对MBO、MBI、MBT反应性的影响规律。理论研究结果表明:在真空中和溶液中,MBO、MBI、MBT的硫酮形式均比其硫醇形式稳定,且反应活性更高,但在溶液中MBO、MBI、MBT存在硫酮-硫醇-离子3种互变形式,其中离子形式反应性最高;作为硫化矿捕收剂,3种苯并杂环巯基捕收剂的捕收能力从大到小的顺序为MBT,MBI,MBO;其选择性从大到小的顺序为MBT,MBI,MBO。The molecular structures of 2-mercaptobenzothiazole（MBT）,2-mercaptobenzoxazole（MBO）,2-mercaptobenzimidazole（MBI） were fully optimized at the B3LYP/6-31＋G（d,p） level in the vacuum phase.The integral equation formalism for the polarizable continuum model（IEF-PCM） was employed to optimize the structures of the three agents and their ions in water with dielectric constant of 78.39.The effects of the O,N and S atoms on the chemical reactivities of MBO,MBI and MBT molecules were inferred by the energies of frontier molecular orbital and the atomic charges which were related to the reactive behavior of them.The results of the calculation indicate that their thione forms of MBO,MBI and MBT are more stable and have stronger reactivities than their thiol forms,both in the vacuum and aqueous phases.But in aqueous phase,there are three forms of thione-thiol-ion tautomerizations for MBO,MBI and MBT,and the ion forms have the strongest reactivities.As collectors for the flotation of sulfide minerals,the following collecting ability order form high to low is theoretically obtained as MBT,MBI,MBO,and their selectivity against pyrite is followed as the order from low to high as MBT,MBI,MBO.

关 键 词：2-巯基苯并噻唑 2-巯基苯并咪唑 2-巯基苯并恶唑 密度泛函理论 化学反应性 

分 类 号：TD923.1[矿业工程—选矿] O641.121[理学—物理化学]